18. The Heart

During which phase or phases of the cardiac cycle does the ventricular pressure change the least?

During which phase of the cardiac cycle do you hear the second heart sound?

You are listening to the heart through a stethoscope. When you hear the first heart sound, which of the following options correctly matches the structure to the pressure change that would be most responsible for producing that sound?

During diastole, a chamber of the heart:

(a) Relaxes and fills with blood

(b) Contracts and pushes blood into an adjacent chamber

(c) Experiences a sharp increase in pressure

(d) Reaches a pressure of approximately 120 mm Hg

During the cardiac cycle, the amount of blood ejected from the left ventricle when the semilunar valve opens is the:

(a) Stroke volume (SV)

(b) End-diastolic volume (EDV)

(c) End-systolic volume (ESV)

(d) Cardiac output (CO)

What is cardiac output, and how is it calculated?

You have been called upon to demonstrate the technique for listening to valve sounds.

Explain where you would position your stethoscope to auscultate.

(1) the aortic valve of a patient with severe aortic valve insufficiency and

(2) a stenotic mitral valve.

During which period(s) would you hear these abnormal valve sounds most clearly? (During atrial diastole, ventricular systole, ventricular diastole, or atrial systole?)

What cues would you use to differentiate between an insufficient and a stenotic valve?

Harvey has a heart murmur in his left ventricle that produces a loud 'gurgling' sound at the beginning of systole. Which valve is probably faulty?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Systole is the contraction portion of the cardiac cycle and diastole is the relaxation portion.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Atrial systole is responsible for ejecting most of the blood into the ventricles during the ventricular filling phase of the cardiac cycle.

Which chamber generates the highest pressure during systole?

a. Right atrium

b. Right ventricle

c. Left atrium

d. Left ventricle

The first heart sound is called ________ and it is caused by the closing of the ________ valves. It occurs at the beginning of the ________ phase of the cardiac cycle. The second heart sound is called ________ and it is caused by the closing of the ________ valves. It occurs at the beginning of the ________ phase of the cardiac cycle.

Cardiac output is equal to:

a. End-diastolic volume minus end-systolic volume.

b. Heart rate multiplied by stroke volume.

c. Stroke volume divided by end-diastolic volume.

d. Heart rate multiplied by preload.